1. Field of the Invention
The present invention relates to a heat dissipation device, and more particularly, to a heat dissipation device with adjusted heat dissipation fins.
2. Description of Related Art
Information technology and computer industrial are highly developed, and therefore portable devices, such as notebook computers, are popularly utilized for business or private purpose. The portable devices have become lighter, thinner and smaller to satisfy the requirements of a modem conveyable working style. Notebook computers are popularly used by the public, because of their powerful processing of digital information.
Due to improvements in semiconductor process technology, the notebook computer function has gradually become more powerful so that the integrated circuits of central processing unit (CPU) have progressively become more complex. However, the complex integrated circuits may cause serious heat dissipation problems. Therefore, the problem of heat dissipation is more serious for a portable device, and especially for a notebook computer, because the interior space thereof is not enough to maintain sufficient airflow by conventional convection. If a heat dissipation problem exists, the internal temperature of the notebook computer increases. As the internal temperature of the notebook computer increases, the operation system thereof may become unstable and the notebook computer may even crash. More seriously, the hardware thereof may be damaged. Hence, the quick dispersion of internal heat is very important for enhancing the operating efficiency of the notebook computer.
For removing the heat generated by a central processing unit, a conventional heat dissipation device uses a high power cooling fan to force the airflow passing through the heat dissipation fins to exchange heat thereon so as to remove the heat from the computer.
FIG. 1 is an airflow velocity distribution diagram of an outlet of a conventional heat dissipation device for a notebook computer. A conventional heat dissipation device utilizes a cooling fan 110 to force air passing through heat dissipation fins 120 to perform the heat exchange so that the heat generated by a central processing unit can be exhausted out of a notebook computer. However, in the conventional heat dissipation device, the airflow velocity, referred to by the arrows, of the cooling fan 110 is not uniform. In an area A, the airflow velocity 130 is lower and the heat dissipation efficiency is therefore lower because the lower airflow velocity 130 reduces the heat exchange efficiency of the heat dissipation fins 120. However, in an area B, the airflow velocity 130 is higher and the heat dissipation efficiency is therefore increased because the higher airflow velocity 130 increases the heat exchange efficiency of the heat dissipation fins 120. However, the noise in the area B is also increased because the higher airflow velocity 130 makes a louder noise while passing through the heat dissipation fins 120.